Charles Holtom from TrioSmartCal did this foloow-up video on the fixed Korad power supply that failed on the EEVblog. • EEVblog #315 - Korad K... www.triosmartcal.com.au
This is the kind of response from a company that will make me buy their product. Its one thing to find a fault and just ignore it, but quite another to admit an issue publicly then openly test the new model with proven corrective action taken. I do wonder how quickly this would have been addressed if it had not been a high profile individual like Dave finding the fault.
Indeed, great response, I wouldn't hesitate to order from them. Would they have done the same for you or me? Well...to be fair, when someone like Dave finds a problem, you have some certainty that it IS indeed a problem. So often, inexperience leads to a false alarm, and since this is an entry-level item (in many ways), false alarms could be expected--but not if it comes from someone like Dave. You can look at his "high profile" status, or you can look at his "knows what is what" status instead.
Its nice to know they fixed the supply (back in 2012 too!). I have three of these babies and Love them, but I got a bit worried when I found the EEVblog review. Then noticed it was from 2012 and began looking to see if it had been fixed since then. And it looks like it had... also in 2012! Whew! Loved the clip lead sparking test, you can't get much better than that! And you kept going with it for a good long time. -Matt
I got the TekPower look alike, TP3005P but can not make the serial commands work. I think I will return it and get this unit. How would one know if the unit has the correct transistors?
The 29 volt on the power supply is the set voltage not the measured voltage. Apparently the supply shows the set voltage while you are setting the voltage (the blinking "9") and when the output is off.
Nice followup review. I have several questions. Could you also show the transient response when turning on/off? I saw there was overshoot on Dave's video, and I am wondering if this issue still exists after their modification. And I wonder if the one in this video is the one with new internal PCB design Dave showed in EEVblog #404 - Korad PSU Followup. Do you know if there is any change in model number since I have no clue how customers can actually tell which one is which without tearing apart if there is no indication outside.
When the supply goes into constant current mode at 10:50 ish, the voltage reading is still 29.00, whilst the DMM says 28.75 - clearly if we're in CC, the voltage would be dropping. Why isn't it reading voltage correctly? (Later on, when he loads M4 - 31V/5.1A, it shows a more correct voltage on the screen.)
What you could do, for a extreme torture test, is get a high current relay and wire it up to short out the supply when it energizes. It will buzz like crazy and probably ruin the relay after 5 minutes but will provide a really good intermittent short test.
is indeed loud but on youtube there is a german guy who has done a really nice mod to greatly lower the fan noise along with a couple of other nice touches. Ive ordered mine and cannot wait to apply those mods to mine. Good luck with yours if you buy one.
Well for a digital controlled lab power supply I will like to see an oscilloscope test to see if it keeps the regulation. Or at least use an LED instead of the incandescent light bulb. If the constant current regulation at the power on off is not kept it will burn the LED or try to change the current or voltage settings when the LED is there of course keeping the current settings within the limit of your LED. I realize this video is old but just for future reference.
Do you have any experience with the Korad KD3005D? I'm having issues with electroplating and switching from CV to CC. Do you know how to do this? Thank you.
I would have liked to have seen it set up where you set a current limit and exceeded it. It is supposed to shut down until it is reset. Geat fearure if it works.
I agree. What sort of product works with 220 and not with 240 (or vice-versa). And how about thermal protection on the transistors if that's what failed before? Having said that I wouldn't pass judgement on the product based on a single bad experience. Maybe Dave just had a dud. It happens.
If you modify your stock yourself, will that nullify any testing organization approvals? Has Korad resubmitted the redesigned unit for testing? Usually you can't just change the design without retesting.
Is this the exactly the same version/model as the previously "KIA" Korad KA3005P (programmable)? I'm sure the differences are minute (if there are any at all) from non-programmable model Korad KA3005D, but a bit of clarification won't harm. p.s. own a regular version and haven't had any issues with it (knock on wood), though hadn't pushed it to the edge yet)
The test is okey, but not as mean as the one that dave did: An electronic load is complex and in it self regulated device as well. With modes like constant power and simulated resistance it is possible to stress the power supply way more then with a bulb. Power Supply and electronic load can go in resonance with each other, a simple bulb won't do that at all. A bulb even acts as negative feedback, because a warmer filament means higher resistance, which means lesser power.
HTML5 mode? Who heard of having hypertext in mpeg data, you are mixing terms, but essentially correct, the MPEG encoder has skipped some frame segments, some of which obviously contained timing data.
I got this power supply too, just with the Velleman name on instead, and it also seems to be an even newer revision. My problem is that I can't find any information about how the over current protection and over voltage protection work, have you figured that out?
OCP : PSU output will switch off when the set current as been reached (so it will not go into CC but switch off instead) OVP : PSU output will switch off when the set voltage has been reached (the PSU has to go into constant current first) So for OVP the PSU has to go from constant voltage to constant current before OVP switches of the output. In OVP mode you could use the PSU as a charger by setting the charging current and target voltage, once the target voltage is reached OVP will switch off the output.
A little late but I hope this is what you were looking for -> www.produktinfo.conrad.com/datenblaetter/75000-99999/094001-an-01-ml-VELLEMAN_PS3005D_LA_de_en_fr_nl_es_pl_pt.pdf
My PSU failed last week. Since I’m electronics engineer I’ve turn it apart and fund that the microprocessor board has malfunction cause of fan short circuit. ULN2003A was blown, I’ve replaced the fan and ULN, to find out that 3 op amps are also shorted (TL082), replaced those but that didn’t help. There was something else short-circuiting 3.3V, found out that it’s a microprocessor with sanded markings. Can you help me in any way with fixing my PSU? I would need a programmed microprocessor, or full microprocessor board.
I know this is a old post, but still, maybe somebody finds this helpful: The microprocessor is most likely a Nuvoton - however I could not find the exact type. You can find the schematic (of a older version of the PSU, and the schematic has errors) here, look for the ZIP file: www.eevblog.com/forum/repair/korad-ka3005p-power-supply-calibration/?all There are different versions of the PSU, with different boards inside.
I'm totally new to the world of electronics and as such know very little. But I am curious why you would be supplying 24v to a car headlamp bulb, when most cars run off a 12v system?
11:10 Whats wrong with the display, why havent anyone asked about this before, is it normal?Its turning off all the indicators except for on the voltage part and one on the current part, display glitch?
So, I now have a choice among these "Korad clones" by a company called RND: 320-KD3005D (two knobs, no buttons) 320-KA3005D (one knob, with buttons) 320-KD3005P (two knobs, no buttons, with USB) and completely different models from UNI-T: UTP3315TFL UTP3315TFL-II (not sure, what they have actually changed for the II version). What do you think? Which, in theory, should be a more reliable choice - the Korad clones or UNI-T?
So what if they were running it on 240V instead of 220V? The mains voltage is rated 220V +-10%. That means the Korad PS should be able to handle up to 242V. Of course, that is if Dave's mains voltage wasn't above 242V. I don't think Korad have a good excuse for their PS failing like that.
lol' you are one of those yt-groupies that are trying to feel better about your master, by second-guessing other channels in lack of actual knowledge. primitive to the core..(mankind in a nutshell) instead of ass-sucking for the big guy on campas (Dave) and in a way to convince yourself that your are subscribed at the best channel, why not evolve yourself so you actually can relate instead of acting ike a little lab-dog in the chase for Dave's affection. there both quite competent in what they are doing...
It is 5 amps at 24 volts into a lightbulb. Unless you stick the 24 volts directly across something moist (like your tongue!) you won't feel anything. The resistance of dry skin is pretty high so you will not get any dangerous current flow.
Finiras You've fallen for the highly deceiving, if not completely wrong "It's the volts that jolt, it's the mill{iamp}s that kill" lie. Yes, you need a certain number of milliamps across your heart to kill you, but in order to cause that to happen you need a large voltage across your body. 24V is not a large voltage, unless maybe you're standing one-legged in a grounded salt-water puddle with a gash in your foot, etc.
